Erosion control system and method

ABSTRACT

Systems and methods for stabilizing a sloped soil surface are provided which generally include a woven or nonwoven matting, blanket, netting, or other porous material anchored to a bare soil surface, and a bonded fiber mulching material injected into the porous material to form a desirable microclimate effective in promoting growth of vegetation.

RELATED APPLICATION

[0001] This application claims the benefit of U.S. provisionalapplication Ser. No. 60/456,358 filed on Mar. 21, 2003, the entiredisclosure of which is incorporated herein by this reference.

BACKGROUND OF THE INVENTION

[0002] The present invention generally relates to erosion controlsystems, and more specifically relates to a system for controlling soilloss on a sloped surface.

[0003] Erosion control is an essential environmental consideration whennew slope embankments are created, for example during construction ofbuildings and drainage systems. Traditionally, the development of rootreinforcement systems are relied upon to control erosion. Methods havebeen developed for stabilizing soil on hillsides and embankments byencouraging the growth of native or introduced vegetation along thesurface. Ideally, a mature root system within the sloped surfacefunctions to bond together the hillside or other sloped surface andinhibits soil loss during rains and other stresses.

[0004] However, embankment surfaces often require reinforcement,particularly during the pre-vegetated stage and early stages of plantgrowth, to prevent loss of soil, seeds, seedlings and other small plantswhen the soil is in an unstable state.

[0005] Various reinforcement systems have been developed. For example,erosion control blankets are commercially available for moderate slopeapplications. Conventional erosion control blankets are typically madeof woven natural or synthetic fibers. These blankets are designed toform a porous, protective covering over a surface prone to erosion.

[0006] A well known problem associated with many conventional erosioncontrol blankets and similar rolled erosion control products is soilmigration which often occurs beneath the blanket, particularly withinpockets and gaps which form if the matting does not closely conform tovarying contours of the terrain. Thus, prior to installation, the slopedsurface is often compacted and leveled. After installation, a commonpractice is to overfill the blanketed surface with granular material toprovide further compaction. Installation of these blankets can be timeconsuming and, unfortunately, the success or failure of the installationwill often not be made apparent until much time has passed.

[0007] Another common practice for controlling erosion on a slopedsurface involves mechanical application of a mulching material to a soilsurface to be stabilized. Mulching materials, for example straw fibers,are often blown onto a bare slope and mechanically incorporated into aloose soil surface by means of crimping techniques using heavyequipment.

[0008] Other methods of controlling erosion include bonded fiber matrixmixtures which are hydraulically sprayed onto a bare slope. These matrixmixtures typically provide only limited, short term erosion controlprotection. For example, these materials are typically utilized in caseswhere rapid germination and vegetation is more likely to occur. Problemsencountered with this form of erosion control includebreaking/fracturing of the bonded fiber matrix layer and lateral surfacemovement due to geo-technical instability or surface traffic. Inaddition, such sprayed mixtures are limited to relatively low gradeslopes and are not suitable for steep slope application due to their lowtensile strength.

[0009] Jacobson, Jr. et al, U.S. Pat. No. 5,330,828, discloses anerosion control matting made of a thermo-mechanically processed, blendedmixture of wood fibers and synthetic fibers.

[0010] Lancaster, U.S. Pat. No. 5,849,645 discloses a reinforcedcomposite matting formed of a coconut fiber matrix and a cuspatednetting forming ridges and troughs extending across a width of thenetting for capturing sediment.

[0011] Kimberlin et al., U.S. patent application Ser. No. 10/072,149,filed on Feb. 2, 2002, teaches a highly effective erosion controlmatting system structured to resist trapping of sediment, for exampleduring a hydraulic event, and protect soil, seeds and seedlings beneaththe matting when the matting is fastened to a sloped surface.

[0012] West et al. U.S. Pat. No. 5,459,181 discloses a hydraulic bindercomposition for covering particulate materials, such as soil, forproviding erosion control.

[0013] Spittle, U.S. Pat. No. 5,942,029 discloses a mechanically bondedfiber mulch including natural and crimped synthetic fibers blended witha polymer-based water absorbent powder.

[0014] The entire disclosure of each of the documents cited hereinaboveis incorporated herein in its entirety by this reference.

[0015] There is still a need for better erosion control systems andmethods. The present invention provides more effective, more technicallyadvanced systems and methods for controlling soil loss erosion, forexample on steeply sloped surfaces.

SUMMARY OF THE INVENTION

[0016] Accordingly, new erosion control systems and methods areprovided, which generally comprise a flexible matting adapted to besecured to or placed on a sloped surface, for example a substantiallynon-vegetated surface.

[0017] In some embodiments of the invention, a method of stabilizing asurface is provided wherein the method generally comprising the steps ofdisposing a porous element, for example a synthetic cellular matting,onto a surface to be stabilized, for example a substantially unvegetatedsoil surface, depositing a flowable material onto the porous element,said flowable material entering openings defined within said porouselement, and allowing the flowable material to set within said openingsto thereby form a desirable microclimate between said matting and saidsurface, said microclimate being favorable to growth of vegetation.

[0018] Preferably, the step of depositing a flowable material isperformed after the step of disposing the porous element on the surfaceto be stabilized.

[0019] For example, in accordance with the present invention, the porouselement may be fixed to the sloped surface to be stabilized byinstalling the porous element to the sloped surface in accordance withconventional installation methods for erosion control matting. Forexample, the porous element may comprise a rolled excelsior erosioncontrol matting. The step of disposing the matting may therefor includeunrolling the matting onto the surface, generally in the direction ofwater flow, and without causing any substantial stretching thereof, suchthat the matting will lie smoothly but loosely on the soil surface.

[0020] The matting may then be affixed to the surface by conventionalmeans, for example, by means of staple fasteners, for example, U-shapedsteel staples placed at spaced apart intervals along the matting.

[0021] Next, in accordance with the present invention, the flowablematerial is deposited onto the porous element. Suitable means fordepositing the flowable material depend at least in part upon the typeof flowable material selected. Preferably, the flowable material is amulch matrix material that when applied in its flowable form, will atleast partially enter openings or pores of the porous element andpreferably, upon setting or solidifying, become affixed to surfaces ofthe porous element.

[0022] In some embodiments of the invention, the flowable material issprayed onto the porous element using conventional mulching apparatus.In other embodiments of the invention, the flowable material is injectedinto the porous element. In a preferred embodiment of the invention, theflowable material is injected into the interstices, pores and openingsof the porous element using conventional mechanical seeding apparatus.

[0023] The present invention also provides systems for stabilizing asurface prone to soil erosion. The present systems generally comprise ablanket element disposed on a surface to be stabilized, and a matrixmaterial incorporated within the blanket element. More specifically, thesystem is installed to the surface by anchoring the blanket element tothe surface, applying a fluid matrix material to the blanket element,and thereafter allowing the fluid matrix material to enter and setwithin openings and cavities within in the blanket element.

[0024] Additional aspects and advantages of the present invention areset forth in the following description and claims, particularly whenconsidered in conjunction with the accompanying drawings in which likeparts bear like reference numerals.

BRIEF DESCRIPTION OF THE DRAWING

[0025]FIG. 1 shows a cross-sectional diagrammatical view of anembodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0026] Accordingly, a method for stabilizing a surface, for example asoil surface prone to erosion, is provided. The method is designed forlong term, steep slope applications which conventionally have beenproblematic in terms of erosion control.

[0027] The method of the present invention generally comprises the stepsof disposing a porous element, for example an erosion control blanket,on a surface to be stabilized, and depositing, for example by injecting,a flowable material onto the porous element. The flowable materialenters openings, for example interstices, pores and/or cavities, definedwithin the porous element. The flowable material is allowed to set, e.g.cure or solidify, within said openings. Once the flowable material isset, the treated erosion control blanket provides an exceptionallystable, desirable microclimate on the soil surface, maintains heat,allows ventilation of gasses, maintains moisture, and resists soil andseedling migration.

[0028] Preferably, the step of depositing a flowable material isperformed only after the porous element has been placed, and preferablysecured to, for example anchored to, the surface to be stabilized. Evenmore preferably, the step of depositing is performed by hydraulicallyapplying the flowable material to the porous element, for example bymeans of conventional equipment. For example, the flowable material maybe applied to the porous element disposed on the surface by means ofsprayers, hydraulic blowers and/or other machinery that isconventionally used to apply mulching material or apply a bonded fibermatrix to a bare soil surface. In accordance with and especiallyadvantageous embodiment of the invention, the flowable material isessentially injected into the porous element, for example usingconventional agricultural seeding apparatus.

[0029] Once the flowable material is set or solidified within the porouselement, the covering formed thereby restrains lateral movement of soilwhile retaining cohesiveness of the sloped surface. The coveringmaintains a healthy microclimate environment on the soil surface, forexample the covering promotes a substantially consistent temperature andholds moisture.

[0030] Preferably, the porous element comprises a natural or syntheticpermanent or temporary erosion control matting, typically supplied in arolled form. For example, the porous element may comprise any a woven ornon-woven blanket, matting or netting, or combinations thereof, forexample, a reinforced fiber blanket made of natural material, forexample, straw, shredded wood, excelsior, coconut fibers and the like,or synthetic materials, for example polyester fibers, polypropylenefibers and the like. The porous element may comprise a relatively heavy,more permanent, three dimensional matting, or a relatively lightweight,substantially two dimensional netting made or natural or syntheticstrands, ropes and the like. In some embodiments of the invention, theporous element comprises a plurality of layers of the same or differentmaterials.

[0031] In a preferred embodiment suitable for long-term, or permanentapplication, the porous element comprises a synthetic, three dimensionalcellular matting, for example having substantial open area, formed ofcavities and pockets with which to hold the bonded fiber matrix or otherflowable material in place. For example, the porous element may comprise3-D Enkamat® manufactured by Colbond Geosynthetics.

[0032] In a preferred embodiment suitable for relatively short term, ortemporary application, the porous element comprises a two dimensionalpolyester or polypropylene netting material. The netting may bephotodegradable and/or biodegradable.

[0033] Preferably, the step of disposing comprises securing the porouselement to the surface prior to the step of depositing the flowablematerial. The porous element may be secured by means of permanent orphotodegradable/biodegradable staples, anchors or any other suitablemeans for holding the mat to the soil surface. Advantageously, it hasbeen found that the present system and methods require relativelyreduced anchoring requirements in comparison to utilizing a erosioncontrol matting alone.

[0034] Preferably, the flowable material comprises a mulching material,more preferably a bonded fiber matrix mixture, for example aconventional bonded fiber matrix mixture. These matrix mixtures comprisefibers or other mulch material that is mixed as a slurry and uponapplication to a slope become bonded, for example by interlocking fibersor by a chemical reaction between ingredients of the mixture. Suchbonded fiber matrix material are well known to those of skill in the artand are commercially available from a variety of sources.

[0035] In accordance with some embodiments of the present invention, theflowable material comprises a hydraulic mulch, for example a mulchingmaterial such as shredded wood, paper, or straw fibers, that is mixedwith water, agitated in a holding tank, and then sprayed onto the porousmaterial.

[0036] In a more preferred embodiment of the invention, the flowablematerial comprises a bonded matrix, a mechanically bonded waterabsorbent mulch, or other suitable material, for example, a bondedmaterial made of natural and/or synthetic fibers mixed with a bondingmaterial, such as a polymer. A suitable mechanically bonded mulch maycomprise, for example, a mixture of up to about 90% or more of a fibermaterial mixed with a polymeric material or a polymeric material mixedwith water. Other suitable flowable materials are disclosed for examplein West et al., U.S. Pat. No. 5,459,181. the disclosure of which hasbeen incorporated herein. The flowable material may comprise a materialmarketed under the name Hydro-Blanket® manufactured by Terra-Mulch. Inother embodiments of the invention, the bonded fiber matrix comprisesfor example the bonded fiber matrix marketed under the name “Soil Guard”and manufactured by Mat, Inc., or another quality matrix material thatwill not substantially rewet and cause loss of mechanical strengthbetween the fibers.

[0037] In accordance with the present invention, the bonded fiber matrixmaterial may be applied to the porous member, for example sprayed ontothe porous member, with or without seeds and/or other additives firstmixed or otherwise incorporated into the bonded fiber matrix mixture orslurry.

[0038] Turning now to FIG. 1, a system for stabilizing a surface proneto soil erosion in accordance with the present invention is showngenerally at 10. The system generally comprises a porous element, forexample, but not limited to a reinforced fibrous blanket 12, disposed ona surface 14 to be stabilized, and a matrix material 16 incorporatedwithin the blanket element 12 wherein the system is made in accordancewith the methods described elsewhere herein.

[0039] For example, the system 10 may be made by installing the blanket12 to the surface 14, anchoring the blanket element 12 thereto, forexample by means of staples 18, and thereafter hydraulically applying orinjecting the matrix material 16 into the blanket 12 while the matrixmaterial 16 is in a flowable form. The combination of blanket 12 andmatrix material 16 is allowed to set and bond to internal and externalsurfaces of the blanket 12, providing an stable, ideal microclimate forplant growth and establishment.

[0040] While this invention has been described with respect to variousspecific examples and embodiments, it is to be understood that theinvention is not limited thereto and that it can be variously practicedwithin the scope of the following claims.

What is claimed is:
 1. A method of stabilizing a surface, the methodcomprising the steps of: disposing a porous element on a surface to bestabilized; depositing a flowable material onto the porous element, saidflowable material entering openings defined within said porous element;and allowing the flowable material to set within said openings, theporous element and set flowable material forming a microclimate on saidsurface favorable to growth of vegetation.
 2. The method of claim 1wherein the step of depositing a flowable material is performed afterthe step of disposing the porous element on the surface to bestabilized.
 3. The method of claim 2 further comprising the step offastening the porous element onto the surface to be stabilized beforethe step of depositing the flowable material.
 4. The method of claim 1wherein the step of depositing comprises the step of injecting theflowable material into the porous element.
 5. The method of claim 4wherein the step of injecting comprises injecting the flowable materialinto the porous element using conventional seeding apparatus.
 6. Themethod of claim 1 wherein the step of depositing comprises hydraulicallyapplying the flowable material to the porous element porous element. 7.The method of claim 1 wherein the step of depositing compriseshydraulically applying a mulching material to the porous element.
 8. Themethod of claim 1 wherein the step of depositing comprises hydraulicallyapplying a bonded fiber matrix material to the porous element.
 9. Themethod of claim 1 wherein the porous element comprises a reinforcedfiber matting.
 10. The method of claim 1 wherein the porous elementcomprises a three-dimensional, cellular matting.
 11. The method of claim1 wherein the porous element comprises a substantially two-dimensionalnetting material.
 12. The method of claim 1 wherein the step ofdisposing comprises securing the porous element to the surface prior tothe step of depositing.
 13. A system for stabilizing a surface prone tosoil erosion, the system comprising: a porous element disposed on asurface to be stabilized; and a matrix material incorporated within theporous element; the system being made by anchoring the porous element tothe surface and thereafter injecting a fluid matrix material into theporous element and thereafter allowing the fluid matrix material to setwithin openings defined within the porous element.
 14. The system ofclaim 13 wherein the porous element is a cellular matting.
 15. Thesystem of claim 13 wherein the porous element comprises a nettingmaterial.
 16. The system of claim 13 wherein the matrix materialcomprises a mixture of fibers bonded with a polymer material.